Amusement display device



Feb. 15, 1966 R. E. WILLIAMS 3,234,847

AMUSEMENT DISPLAY DEVICE Filed Jan. 18, 1962 INVENTOR EmHAQD 'E.\A/IL.L\AM5 ATTORNEYS United States Patent 3,234,847 AMUSEMENT DISPLAY DEVICE Richard E. Williams, Fairfax, Va., assig'nor to Scope, In-

corporated, Falls Church, Va., a corporation of New Hampshire Filed Jan. 18, 1962, Ser. No. 167,028 7 Claims. (Cl. 88-24) The present invention relates generally to an amusement display device and more particularly to -a randomly variable diffuse amusement display responsive to a random audio signal.

In the present invention, a randomly variable diffuse display is presented on a translucent viewing screen by means of variable intensity omni-directional light sources. Light from each of the sources is propagated by a plurality of direct and indirect path through a rotating pat tern carrying screen. The pattern imposed on the screen consists of sharply defined opaque areas rather than diffuse areas but the exhibited display is diffuse because of the multiplicity of light paths between the source, the pattern, and the viewing screen.

The intensityo-f the light sources is randomly varied in response to a random wide band audio signal, such as produced by the spoken word or music from a tape recorder, phonograph record. To obtain a completely varied patern, two independently variable light sources are provided. One of the light sources is responsive to only the low frequency band envelope of the audio signal while the other light source is responsive only to theenvelope of the audio signal high frequency band.

Transistor circuitry is provided to' control the intensity of the light sources. The transistor circuitry which controls each light source, acurrent responsive light bulb, comprises a clipper detector for the audio signal envelope applied thereto. The detector comprises a capacitor connected between the emitter and collector of the transistor. To detect the audio enevelope, a capacitance of extremely large value, for example. 1000 microfarads, is employed. If the signal applied to the detector suddenly increases in amplitude to a great extent, the current surge applied through the transistor by the large capacitor, may cause the transistor to burn out. To prevent this from occurring, a small current limiting resistance is connected in series with the capacitor to prevent its sudden discharge through the transistor. The impedance of the resistor under normal operating conditions is suflioently small to have virtually no effect upon the charge stored by the capacitor.

For Wide public acceptance, an amusement display device must be capable of inexpensive manufacture and of utilizing inexpensive and similar parts. In the device of the present invention, only transistors of the same type are employed in the circuit for the power rectifier, detectors and audio amplifier. Because of the slow speed which the display disc is rotated, the motor employed is of small torque and accordingly quite inexpensive.

In one embodiment of the present invention, the apparatus is completely maintained in a single housing. For certain applications it is desired to place a display consisting of a plurality of randomly varying light bulbs at a inaccessible location. Under such circumstances, the control circuit is maintained remote from the display but proximate the signal source, to obviate the need for an additional amplifier between the signal source and the control circuit. Also, such an arrangement is advantageous because it permits the control circuit housing to be maintained in an unexposed location so that it is not necessary to provide expensive means to protect the circuit from the elements.

3,234,847 Patented Feb. 15, 1966 It is an object of the present invention to provide a new and improved amusement display device wherein a completely random variable display is presented.

It is another object of the present invention to provide a randomly variable amusment display device having a light source controlled by a randomly variable audio signal.

It is a further object of the present invention to provide a new and improved amusement display device employing a plurality of variable, random intensity light sources which are responsive to different audio frequency bands.

It is still another object of the present invention to provide a diffuse pattern display device employing a transparent pattern carrying medium having sharply defined opaque patterns thereon.

It is still another object of the present invention to provide a new and improved amusement display device which produces a randomly variable, diffuse pattern, wherein said device employs a plurality of variable intensity light sources having a plurality of direct and indirect light paths through a transparent rotating wheel having a sharply defined opaque pattern areas imposed thereon.

Still another object of the present invention is to provide a new and improved transistorized audio frequency envelope detector wherein the transistor is not subject to burn out.

It is still another object of the present invention to provide a new and improved audio frequency envelope detector employing a large capacitor across opposed terminals of said transistor and a current limiting impedance in series with said capacitor to prevent burn out of the transistor.

Another object of the present invention is to provide a new and improved circuit for controlling the intensity of a plurality of light sources in a completely random and different manner from each other.

Yet a further object of the present invention is to provide a new and improved circuit for controlling the intensity of a plurality of light sources in a variable manner, each of said sources being responsive to different frequency components of an audio signal which varies in a random manner, such as music or speech.

It is another object of the present invention to provide a new and improved amusement display device which produces a randomly variable, diffuse light pattern which employs inexpensive and similar parts.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a schematic diagram of the optical system according to the present invention;

FIGURE 2 is a schematic diagram of the electronic circuitry utilized to control the light sources of FIG- URE 1;

FIGURE 3 illustrates a housing for the display screen and control mechanism of the present invention; and

FIGURE 4 is an illustration of another embodiment of the present invention wherein the control mechanism is remotely located from the display housing.

Reference is now made to FIGURE 1 of the accompanying drawings which illustrates a translucent viewing screen 11 upon which light from lamps 12 and 13 is propagated. Lamps 12 and 13 propagate diffuse, unfocused and uncollimated omni-directional light beams in wide beam paths. The intensity of light emitted by lamps in response to an audio signal, as will be seen infra.

12 and 13 is varied in a completely random manner Disposed in a plane between light sources 12 and 13 and translucent viewing screen 11, is a rotatable, transparent disc 14 having sharply defined, opaque pattern areas 20 located thereon. A disc having sharply defined opaque and transparent areas is facile and economical to manufacture and therefore very desirable in the present system. Disc 14 is rotated at a slow rate of speed, 1-2 revolutions per minute, by motor 15 which drives shaft 16 at the center of the disc.

To form a diffuse pattern on translucent screen 11, a multiplicity of both direct and indirect diffuse light paths are formed between lamps 12 and 13 and screen 11. The indirect light paths are established by a reflecting means such as mirrors 17 and 18, positioned on the side of lamps 12 and 13 opposite to that of disc 14. Thus because of the multiplicity of different light paths between the lamps 12 and 13, and screen 11, and the different angles which the various beams strike the pattern, the sharp edges blend in with the transparent areas as the disc rotates. The variable intensity light emitted by lamps 12 and 13 also results in a further diffusion of the image formed on screen 11. The overall eifect is quite unusual and pleasing to the eye.

To control the intensity of the light emitted by lamps 12 and 13, in completely random and different manners, the circuit of FIGURE 2 is provided. The circuit of FIGURE 2 includes four PNP transistors 21, 22, 23 and 24 which are preferably all of the 2N176 type. DC. power for transistors 21, 22 and 23 is provided by the power supply constituting transistor 24, transformer 25, switch 26 and conventional A.C. plug 27, which is adapted to be connected to a source of 60 cycle, 110 volt power. The A.C. plug 27 is connected to the primary of transformer 25 through switch 26 when the circuit is operating. To provide an indication that the circuit is operating in response to closure of switch 26, an indicator light 28 is connected across primary winding of transformer 25. One end of the secondary winding of transformer 25 is connected to the base of transistor 24, while the other end is connected to one plate of capacitor 29 via terminal 30. The collector of transistor 24 is connected to one terminal of power supply resistor 31, the other terminal of which is connected to capacitor 29. Since the emitter of transistor 24 is unconnected, this transistor serves as a power rectifier. The series combination of resistor 31 and capacitor 29 functions as a smoothing circuit for the half-wave rectified voltage developed by transistor 24. In consequence, a positive DC. voltage is developed at terminal 30 relative to the collector of transistor 24.

Power for operating audio amplifier transistor 21 is derived from the common junction 40 between resistor 31 and capacitor 29. Load resistor 32 for transistor 21 is connected between junction 40 and the collector of transistor 21. DO. base stabilization of transistor 21 is obtained by feedback resistor 33, connected between the transistor collector and base. Bias and hence gain control of transistor 21 is provided by adjusting the slider of rheostat 34, which is connected between the transistor base and emitter. Transistor 21 amplifies the audio signal applied thereto from a wide band randomly variable audio signal source, such as voice or music signals, which are produced by a microphone or voice coil connected between input terminals 35 and 36. Connected across terminals 35 and 36 is resistor 37 for matching the impedance of the signal source. The audio signal across terminals 35 and 36 is coupled to the base of transistor amplifier 21 by a current limiting resistor 38.

Transistor 21 amplifies the audio signal applied to it across terminals 35 and 36 in a conventional manner and drives a pair of filters 39 and 41 through a resistancecapacitance coupling circuit. The coupling circuit includes capacitance 42, connected to the collector of transistor 21, and resistor 43, connected between the opposite plate of capacitor 42 and terminal 30. Low pass filter 39 includes resistor 44, connected to the junction between resistor 43 and capacitor 42, and capacitor 45, connected between the emitter and base of transistor 23. High pass filter 41 includes capacitor 46, connected to resistor 43 and the base of transistor 22, and resistor 47, connected in shunt with the base and emitter of transistor 22.

Filters 39 and 41 are selected to have the same cut-off frequency, approximately 500 cycles. Thus, if the fre quency of the audio signal across resistor 43 increases above 500 cycles the output voltage across capacitor 45 of the filter 39 decreases at the rate of 3 db per octave while the output voltage of filter 41 is substantially unattenuated while the opposite condition prevails for signals decreasing in frequency below 500 cycles.

Transistors 22 and 23 are responsive to the output voltages of high pass and low pass filters 41 and 39, respectively. The collectors of transistors 22 and 23 are connected to the negative terminal of the power supply via lamps 48 and 49, respectively. The emitters of both transistors 22 and 23 are connected to the positive terminal 30 of the power supply and their bases are normally unbiased relative to their emitters. In consequence, alternate half cycles of the A.C. input signals applied to the bases of transistors 22 and 23 drive the transistors to cut-off, thereby eliminating or clipping one half of the input wave form in the output of transistors 22 and 23.

Connected across the emitter and collector of transistors 22 and 23 are audio envelope detection networks including capacitors 51 and resistors 52. Since capacitors 51 do not permit the voltage between the emitter and collector of transistors 22 and 23 to change instantly, they serve to maintain the current flow through lamps 48 and 49 constant relative to high frequency variations of the inputs applied to the detector transistors 22 and 23. The capacitors 51 are designed of such value as to detect the audio frequency envelope of the signals applied to transistors 22 and 23. For this purpose, capacitors 51 have -a value of approximately 1,000 microfarads.

Resistors 52 are connected in series with capacitors 51 to prevent excessive current from flowing through transistors 22 and 23 when a high frequency fluctuation of the input signals applied to the transistors occurs. If the impedance of transistors 22 and 23 suddenly decreases due to a large signal of high frequency being applied to the bases thereof, capacitors 51 have a tendency to discharge substantial amounts of current through the transistors. This high current flow frequently results in transistor burn out if a protective impedance, such as resistor 52 is not employed. By utilizing resistor 52 which may have a value of approximately 1 ohm, extremely high amplitude, short duration surges from capacitor 51 through transistors 22 and 23 do not occur in response to rapid fluctuations of the A.C. signal and transistor burn out is obviated. The resistances 52 are designed to be of sufficiently low value to permit capacitors 51 to charge up to voltage substantially equal to that across the emitters and bases of transistors 22 and 23. Thus resistances 52 affect the charge and discharge currents of capacitors 51 only when the audio signal, which makes up the audio envelope, is of considerably greater frequency than the envelope.

Lamps 48 and 49 vary their intensity in a random and different manner in response to the audio signalacross terminals 35 and 36 because of the random nature of the input signal and because of the inclusion of the high and low pass filters 41 and 39. If the audio signal contains predominantly low frequency signals, lamp 49 is illuminated to a considerably greater extent than lamp 48 while the contrary is true for signals having mostly high frequency components. As the frequency components of the input signal change, the intensity of light emitted by lamps 48 and 49 is accordingly varied in acordance with the envelope and hence amplitude of the signal in the low and high frequency bands defined by filters 39 and 41.

Reference is now made to FIGURE 3 of the accompanying drawings which illustrates a right parallelepiped 53 in which all of the apparatus of the present invention is mounted. Mounted upon one face of parallelepiped 53 is translucent screen 11. The complete control apparatus including the disc and illumination system of FIGURE 1 and the control system of FIGURE 2 is located interiorly of the parallelepiped 53. The parallelepiped is constructed to be impervious to light from external sources. The translucent screen 11 is illluminated by lamps 12 and 13 located within the parallelepiped 53 by the effect commonly refered to as back illuminating.

FIGURE 4 illustrates a plurality of separately energized lamps 48 and 49 positioned on Christmas tree 56, at various points inaccessible to an audio signal and exposed to the elements. Lamps 48 and 49 are connected to each other by parallel or series circuit, as well known in the art. Positioned in sheltered building 58 are an audio signal source, tape recorder 59, and housing 54 for the control circuit of FIGURE 2. The control circuit is responsive to the signal picked up by the voice coil of recorder 59 and applies variable amplitude signals via cable 57 to the lamps 48 and 49, the amplitude of the signals corresponding with the envelopes of the high and low frequency bands. It is important that the control circuit housing 54 be located proximate recorder 59 so that external amplifiers need not be employed. Also, by placing housing 54 within building 58, there is little need for expensive weather protecting structure on housing 54.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. A system for providing a randomly variable diffuse pattern in response to a wideband frequency signal source varying in a random manner, such as music or speech, comprising a viewing screen, a plurality of variable intensity light sources each positioned to propagate an omni-directional light beam having a multiplicity of different paths onto said screen, a transparent pattern carrying medium movable in a plane between said source and said screen, the pattern on said medium having only sharply opaque areas, a plurality of filters having different pass bands responsive to said source, means for clipping alternate half cycles of said signal source, a plurality of envelope detectors, one for each of said filters, for detecting the envelope derived from the output of each of said filters whereby flicker is eliminated, and means for separately coupling the output of each of said envelope detectors to a respective one of said light sources.

2. The system of claim 1 further including means for reflecting light emanating from each of said light sources onto said medium and screen, said last named means being positioned on the opposite side of said light sources from said pattern.

3. The display system of claim 1 wherein each of said signal envelope detectors comprises an electric discharge device having an electrode for emitting charged carriers, an electrode for collecting said carriers and a control electrode disposed between said emittting and collecting electrodes for proportionately controlling the current between said emitting and collecting electrodes in response to the signal amplitude applied by each of the filter means between the emitting and control electrodes, a series circuit including a capacitor and a current limiting impedance shunting said collecting and emitting electrodes, said capacitor being of such value as to detect the envelope of the signal applied by the respective filter to the control and emitting electrodes of said devices, said current limiting impedance being of such value as to substantially affect the discharge current of said capacitor only when the signal frequency is high compared to the envelope frequency, means for supplying a DC. biasing potential for the collecting and emitting electrodes, and means connecting said light source in DC. circuit between said bias source and the emitting and collecting electrodes.

4. A system for providing a randomly variable diffuse pattern display in response to a randomly variable wide band audio frequency source, such as music or speech, comprising a viewing screen, a plurality of variable intensity light sources each positioned to propagate an omnidirectional light beam having a multiplicity of different paths onto said screen, the intensity of said light sources being dependent upon the voltages across them, a transparent pattern carrying medium movable in a plane between said source and said screen, the pattern on said medium having only sharply defined opaque areas, means for rotating said pattern at a rate on the order of l to 2 revolutions per minute, a plurality of filters having different pass bands and each responsive to said source, means for clipping alternate half cycles of said signal source, a plurality of envelope detectors, one for each of said filters, for separately detecting the envelope derived from the output of each of said filters whereby flicker is eliminated, and means for separately coupling the output signal of each of said envelope detectors to a respective one of said light sources.

5. A system for providing a randomly variable diffuse pattern display in response to a randomly variable, wide band audio frequency source, such as music or speech, comprising a viewing screen, a pair of variable intensity light source each positioned to propagate an omnidirectional light beam having a multiplicity of different paths onto said screen, each of said light sources deriving a light intensity dependent upon the voltage across it, a transparent pattern carrying medium movable in a plane between said source and said screen, the pattern on said -medium having only sharply defined opaque areas, a low pass RC filter, a high pass RC filter, means connecting said filters in parallel with said randomly varying source, a separate envelope detector responsive to the output of each of said filters, each of said envelope detectors including an electric discharge device having: an electrode for emitting charged carriers, an electrode for collecting said carriers and a control electrode disposed between said emitting and collecting electrodes for controlling the number of carriers reaching said collecting electrodes proportionately dependent upon the voltage between said emitting and control electrodes; means for biasing said electric discharge devices so that approximately one half the signal content of the AC. waves coupled to them through the filters is clipped, a series circuit including a capacitor and a current limiting impedance shunting said collecting and emitting electrodes, said capacitor being of such value as to detect the envelope of the signal applied between the control and emitting electrodes, said current limiting impedance being of such value as to substantially affect the discharge current of said capacitor only when the signal frequency is high compared to the envelope frequency, means for establishing a DC. bias voltage for energizing the path between the emitting and collecting electrodes of said devices, and means for connecting each of said lamps in a DC. circuit between the DC. bias supply and the emitting and collecting electrodes of said devices so that each light source is responsive to the detected signal envelope.

6. The display system of claim 5 wherein said capacitance has a value on the order of 1000 microfarads and said resistance has a value on the order of one ohm.

7. A system for providing a randomly variable diffuse pattern display comprising a randomly variable, Wide band audio frequency source, a viewing screen, a pair of variable intensity light sources each positioned to propagate an omni-directional light beam having a multiplicity of different paths onto said screen, each of said light sources deriving a light intensity dependent upon the voltage across it, a transparent pattern carrying medium movable in a plane between said source and said screen, the pattern on said medium having only sharply defined opaque areas, a low pass RC filter, a high pass RC filter, means connecting said filters in parallel with said randomly varying source, a separate envelope detector reenvelope detectors including an electric discharge device having: an electrode for emitting charged carriers, an sponsive to the output of each of said filters, each of said electrode for-collecting said carriers and a control electrode disposed between said emitting and collecting electrodes for controlling the number of carriers reaching said collecting electrodes proportionately dependent upon the voltage between said emitting and control electrodes; means for biasing said electric discharge devices so that approximately one half the signal content of the AC. waves coupled to them through thefilters is clipped, a series circuit including. a capacitor and a current limiting impedance shunting said collecting and emitting electrodes, said capacitor being of such value as to detect the envelope of the signal applied between the control and emitting electrodes, said current limitingimpedance being of such value as to substantially affect the discharge current of said capacitor only when the signal frequency is high compared to the envelope frequency, means establishing a DC. bias voltage for energizing the pathbetween the emitting and collecting electrodes of said devices, and means for connecting each of said lamps in a DC. circuit between the DC. bias supply and the emitting and collecting electrodes of said devices so that each light source is responsive to the detected signal envelope.

References Cited by the Examiner UNITED STATES PATENTS 1,891,216 12/1932 Hough.

2,099,904 11/1937 Pennington et al. 88-24 2,196,423 4/ 1940 Musaphia 40106.53 2,281,790 5/1942 Newhall 40-130 X 2,345,445 3/ 1944 Atwood 250199 2,389,649 11/1945 Stark et al 250199' 2,665,609 l/1954 Gilluly 88-24 2,900,507 8/1959 Rogers 329-102' 2,988,704 6/1961 Walker et al. 329102 3,062,085 11/1962 Smith 84464 NORTON ANSHER, Primary Examiner.

WILLIAM MISIEK, Examiner. 

1. A SYSTEM FOR PROVIDING A RANDOMLY VARIABLE DIFFUSE PATTERN IN RESPONSE TO A WIDEBAND FREQUENCY SIGNAL SOURCE VARYING IN A RANDOM MANNER, SUCH AS MUSIC OR SPEECH, COMPRISING A VIEWING SCREEN, A PLURALITY OF VARIABLE INTENSITY LIGHT SOURCES EACH POSITIONED TO PROPAGATE AN OMNI-DIRECTIONAL LIGHT BEAM HAVING A MULTIPLICITY OF DIGFERENT PATHS ONTO SAID SCREEN, A TRANSPARENT PATTERN CARRYING MEDIUM MOVABLE IN A PLANE BETWEEN SAID SOURCE AND SAID SCREEN, THE PATTERN ONS AID MEDIUM HAVING ONLY SHARPLY OPAQUE AREAS, A PLURALITY OF FILTERS HAVING DIFFERENT PASS BANDS RESPONSIVE TO SAID SOURCE, MEANS FOR CLIPPING ALTERNATE HALF CYCLES OF SAID SIGNAL SOURE, A PLURALITY OF ENVELOPE DETECTORS, ONE FOR ECACH OF SAID FILTERS, FOR DETECTING THE ENVELOPE DERIVED FROM THE OUTPUT OF EACH OF SAID FILTERS WHEREBY FILCKER IS ELIMINATED, AND MEANS FOR SEPARATELY COUPLING THE OUTPUT OF EACH OF SAID ENVELOPE DETECTORS TO A RESPECTIVE ONE OF SAID LIGHT SOURCES. 